String Functions in Pascal

Our program demonstrates various string-related functions in Pascal. Here’s the full source code:

program StringFunctions;

uses
  SysUtils;

procedure PrintLine(const s: string);
begin
  WriteLn(s);
end;

var
  p: procedure(const s: string);

begin
  p := PrintLine;

  // Here's a sample of string functions available in Pascal.
  // Some of these are part of the standard library, while others
  // are from the SysUtils unit.

  p('Contains:  ' + BoolToStr(Pos('es', 'test') > 0, True));
  p('Count:     ' + IntToStr(Length('test') - Length(StringReplace('test', 't', '', [rfReplaceAll]))));
  p('HasPrefix: ' + BoolToStr(Copy('test', 1, 2) = 'te', True));
  p('HasSuffix: ' + BoolToStr(RightStr('test', 2) = 'st', True));
  p('Index:     ' + IntToStr(Pos('e', 'test') - 1));
  p('Join:      ' + StringReplace('a,b', ',', '-', [rfReplaceAll]));
  p('Repeat:    ' + StringOfChar('a', 5));
  p('Replace:   ' + StringReplace('foo', 'o', '0', [rfReplaceAll]));
  p('Replace:   ' + StringReplace('foo', 'o', '0', []));
  p('Split:     ' + '[' + StringReplace('a-b-c-d-e', '-', ' ', [rfReplaceAll]) + ']');
  p('ToLower:   ' + LowerCase('TEST'));
  p('ToUpper:   ' + UpperCase('test'));
end.

To run the program, save it as string_functions.pas and compile it using a Pascal compiler like Free Pascal:

$ fpc string_functions.pas
$ ./string_functions
Contains:   TRUE
Count:      2
HasPrefix:  TRUE
HasSuffix:  TRUE
Index:      1
Join:       a-b
Repeat:     aaaaa
Replace:    f00
Replace:    f0o
Split:      [a b c d e]
ToLower:    test
ToUpper:    TEST

This example demonstrates various string manipulation functions in Pascal. Some key differences from other languages:

Pascal uses 1-based indexing, so the Index function returns 1 for the first occurrence (equivalent to 0 in many other languages).
The StringReplace function is used for both Replace and Join operations.
Pascal doesn’t have a built-in Split function, so we simulated it using StringReplace.
The BoolToStr function is used to convert boolean results to strings.

These functions provide a good starting point for string manipulation in Pascal. For more advanced string operations, you might need to implement custom functions or use additional libraries.

Recover in Pascal

String Formatting in Pascal

Learn X By Example

Title here

String Functions in Pascal